This costume is perfect because it can be done within big or small groups, or on your own. You can draw inspiration from the Rainbow Magic books, where each character is a fairy named after a color, or Winx Club and Pixie Hollow.
I would apply glitter makeup under my eyes, using the the NYX Professional Makeup Body Glitter.
Little Red Riding Hood
I think the Girl Scout costume is adorable, and although you may have less of these items already in your closet compared to other costumes, it’s worth it if you have the means to obtain them, IMO.
You can leave the sash plain, or go to your local craft store and pick out some iron-on patches for some DIY action. And it’s customizable that way!
Angel(s) & Devil
Many times I’ve dressed up for Halloween with a headband as my sole accessory, and I have no shame in that. With this costume you can do an angel/devil duo or angel/fallen angel duo, as well as a trio with all three.
You can add matching wings or a devil’s tail for more pizazz, but it isn’t necessary. Pair these with a monochrome outfit according to your headband and you’re good to go.